Mr. WRIGHT: David Wright watches his eighth-inning double that drove in the go-ahead run during the Mets’ 9-4 win at Citi Field. Photo: Anthony J. Causi

FLU THE MAN: David Wright, who despite battling flu symtoms, went 2-for-2 with three walks to raise his average to an MLB-best. 411, is congratulated after scoring the tying run in the seventh inning. (Anthony J. Causi)

Every time these Mets get knocked down, they find a way to get back up off the mat. And as usual, it was David Wright who picked them up yesterday.

With the Mets staring at a third straight loss, Wright — suffering from flu symptoms — led a rally that turned a four-run deficit into a 9-4 come-from-behind victory over the Reds.

He showed leadership Tuesday by wanting to stay in the game for any reprisal the Brewers chose to mete out after D.J. Carrasco beaned Ryan Braun. And he showed it again yesterday by playing sick, working walks when the Reds didn’t pitch to him and punishing them when they did. He scored the tying run in the seventh and drove in the go-ahead run in the five-run eighth.

“I’ve never seen anything like it. It’s unbelievable. You just look up and he’s on base,’’ said Terry Collins, who likened Wright’s form to Barry Bonds, whom he coached in Pittsburgh. “I compare what David’s doing to what I saw Bonds do when Barry was in Pittsburgh, hitting fifth without a lot of bombers behind him.’’

The Mets had lost three of four and trailed the Reds 4-0 before matching their biggest comeback in a season rife with comebacks. This one lifted them to 21-17 — 2 1/2 games behind NL East-leading Braves — and Wright was at the heart of it, now hitting a major league-leading .411.

“[My cold] was a lot worse [Wednesday] night. I didn’t feel all that great, but good enough to go out there and play. It makes it feel a lot better to win, so it’s all good,’’ Wright said. “As long as I can feel like I can help the team more than hurt them, I feel like I can play.’’

The Mets scored two in the fifth and one in the sixth to pull within 4-3, then tied it in the seventh. Aroldis Chapman hadn’t allowed a run in 19 1/3 innings, but Wright worked a leadoff walk and Lucas Duda singled. Daniel Murphy

The Mets blew it open in the eighth against Logan Ondrusek (3-1). Backup catcher Rob Johnson laid down a one-out bunt single, and when the Reds finally gave Wright something to hit, he drilled a double over Stubbs’ head that one-hopped off the wall to plate Johnson. Wright scored on Turner’s RBI single and Ronny Cedeno tacked on a three-run home run.

“He got four pitches to hit and two go for doubles, one off the center-field wall. He’s outstanding,’’ said Murphy, who turned a brilliant sixth-inning double play on Jay Bruce. “I’m going to go give him a big ol’ hug. Maybe it’ll rub off on me a little bit.’’

The bullpen actually held on to a lead, with Jon Rauch and Bobby Parnell (1-0) each pitching scoreless innings before closer Frank Francisco did the same in a non-save ninth.